1. Field of the Disclosure
The disclosure relates generally to electronic devices, and more specifically, to electronic devices including spaced-apart radiation regions and processes for forming the same.
2. Description of the Related Art
Electronic devices, including organic electronic devices, continue to be more extensively used in everyday life. Examples of organic electronic device include Organic Light-Emitting Diodes (“OLEDs”). Manufacture of such devices can require control over the spreading of deposited liquid compositions. Typically, this has been accomplished by the use of an organic or inorganic material deposited over a panel to form a bank structure to help prevent the flow of the liquid composition into undesirable areas. The bank could be fluorinated to improve the confinement through an increased contact angle and reduced surface energy.
Alternative methods have been used in which a receiving layer is use to rapidly increase the viscosity of a deposited liquid composition, and therefore, reduce the spreading of the liquid composition laterally and help to prevent overflow into neighboring pixels. The receiving layer can be formed by spin-coating material over the surface of the workpiece prior to placement of the liquid composition. The receiving layer can help reduce possible negative interactions between the liquid composition and the surface of the workpiece and may eliminate the need for a plasma surface treatment prior to application of the liquid composition.
However, for resolution greater than approximately 100 pixels per square inch, a thicker receiving layer may be required to achieve the needed control in line width. An increase in receiver layer thickness could negatively impact both the efficiency and operating voltage of the display if the receiving layer reduces the electrical, optical, or any combination thereof, properties of the emission materials. The uniformity of the diffusion of the deposited liquid composition into the receiver layer can also be difficult to control and cause visual differences across the panel. Such visual differences can be the result of emission of a different spectrum or intensity from portions of the panel designed to be the same. Adjusting for these differences can use a portion of the adjustment range that could otherwise be used to extend the usable life of the electronic component.
A different conventional process uses a vapor or solid phase diffusion process. Both processes suffer from similar problems previously described. If the diffusion is long enough to make the concentration of a deposited material more uniform throughout a thickness of the layer (i.e., reduce the concentration gradient between the electrodes), lateral diffusion will be too large and can result in low resolution because the pixels will need to be large. Alternatively, if lateral diffusion can be kept at an acceptable level for high resolution, the guest material concentration gradient throughout the thickness of the organic layer may be unacceptably large. In some instances, both problems may occur (i.e., unacceptably large lateral diffusion while having too severe of a concentration gradient between the electrodes of the electronic device).